Abstract: A die having large numbers of grooves for molding a material to a honeycomb structure, wherein a surface having the grooves has an outer periphery in a polygonal shape having 6 or more corners, and wherein the grooves are crossing the outer periphery at an angle of 30° or more.

Abstract: A method for producing a die for molding a ceramic honeycomb structure, which has molding grooves arranged in a lattice pattern and apertures communicating with the molding grooves for supplying a moldable material, wherein the formation of the lattice-patterned grooves by machining is conducted by a first machining operation for forming pluralities of first parallel grooves, and a second machining operation for forming second grooves crossing the first grooves; wherein the first and second machining operations are conducted by at least 2 passes of grinding or cutting using a rotating tool; and wherein the second machining operation is conducted by up-cutting in the second pass or later, and a method for producing a ceramic honeycomb structure using such a die.

Abstract: A method for producing a die for molding a ceramic honeycomb structure, which has molding grooves arranged in a lattice pattern and apertures communicating with the molding grooves for supplying a moldable material, wherein the formation of the lattice-patterned grooves by machining is conducted by a first machining operation for forming pluralities of first parallel grooves, and a second machining operation for forming second grooves crossing the first grooves; wherein the first and second machining operations are conducted by at least 2 passes of grinding or cutting using a rotating tool; and wherein the second machining operation is conducted by up-cutting in the second pass or later, and a method for producing a ceramic honeycomb structure using such a die.

Abstract: A die having large numbers of grooves for molding a material to a honeycomb structure, wherein a surface having the grooves has an outer periphery in a polygonal shape having 6 or more corners, and wherein the grooves are crossing the outer periphery at an angle of 30° or more.

Abstract: The differential apparatus comprises (a) a casing rotated by a driving force from outside; (b) a pair of opposing disc plates coaxially disposed in the casing, an opposing surface of each disc plate being formed with a circumferentially continuous groove winding such that a radial position changes at a constant period; (c) a plurality of balls rolling in opposing winding continuous grooves of both disc plates; and (d) a ball holder rotating integrally with the casing and having a plurality of radially extending guide holes, each guide hole movably receiving each ball, wherein the winding continuous groove of each disc plate circumferentially continuously has first guide regions each extending from a radially outer position to a radially inner position of each disc plate and second guide regions each extending from a radially inner position to a radially outer position, inflected regions each connecting each first guide region and each second guide region being larger in width and/or depth than the first guide